An aspect of the present disclosure is directed to a method for mitigating rotor bow in a turbo machine. The method includes rotating a rotor over a first period of time; discontinuing rotation of the rotor for a second period of time; and iterating, over an overall period of time, rotation of the rotor over the first period of time and discontinuing rotation of the rotor for the second period of time.

A method for supplying air to an engine of an aircraft via an air supply system of the aircraft. A dynamic air intake vent of the system can be closed by a closure member that is movable between a closed position and an open position. A static air intake vent is equipped with a filter medium. During flight, the method comprises an unfiltered operating mode that comprises the following steps: positioning of the closure member in the open position, and, during a phase of forward travel of the aircraft, dynamic intake of a flow of air, then transfer of a first portion of the flow of air to the engine and a second portion of the flow of air to the filter medium in order to clean the filter medium.

A turning system for rotating equipment, comprises a motor configured for speed control; a gear connected to the motor, the gear is further connected to the rotating equipment, the motor and gear are configured for rotating the rotating equipment at speeds less than the normal operating speed of the rotating equipment; and a controller configured to perform a method, wherein the method comprises a sequence of steps including, rotating the rotating equipment from a standstill an angular amount of rotation, stopping rotation after moving the angular amount of rotation, and maintaining the rotating equipment at a standstill for a period of time; and repeating the sequence of steps. By performing the sequence of steps after the rotating equipment comes to a standstill, bowing or sagging of the rotating equipment can be prevented, and the rotating equipment is ready to startup at anytime.

An aircraft engine, comprising: a first wall and a second wall defining a gaspath between the first wall and the second wall, the gaspath extending around a central axis, each of the first wall and the second wall having a gaspath side facing the gaspath and an opposed side facing away from the gaspath; struts circumferentially distributed around the central axis, the struts extending across the gaspath, a strut of the struts having an airfoil including a leading edge, a trailing edge, a first end secured to the first wall, and a second end secured to the second wall; and protrusions extending from a baseline surface of the opposed side of the first wall, the protrusions increasing a thickness of the first wall, a protrusion of the protrusions overlapping a location where the leading edge or the trailing edge meets the gaspath side of the first wall.

A turbine stator sector includes a plurality of vanes extending along a radial direction between a first end and a second end and along an axial direction between a leading edge and a trailing edge. The sector further includes an internal shroud linked to the first end of the vanes and an external shroud linked to the second end of the vanes. The sector includes at least one annular portion forming all or part of the internal shroud or of the external shroud. The annular portion includes a first partition present at the junction with the first or the second end of the vanes and a second partition held spaced from the first partition along the radial direction by a three-dimensional structure including a plurality of cutouts.

A method of starting a gas turbine engine is generally provided. The engine includes a rotor assembly including a compressor rotor and a turbine rotor each coupled to a shaft. The rotor assembly is coupled to a bearing assembly within a casing enabling rotation of the rotor assembly. The method includes determining, based on a lubricant parameter, a period of time within which a rotational speed of the rotor assembly is maintained within a bowed rotor mitigation speed range; rotating the rotor assembly for the period of time within the bowed rotor mitigation speed range; and accelerating the rotor assembly to the combustion speed to ignite a fuel-oxidizer mixture for combustion.

A turbine assembly can include a turbine housing that defines a longitudinal axis and that includes a first scroll and a first tongue at a first angle about the longitudinal axis and a second scroll and a second tongue at a second angle about the longitudinal axis, where an angular span between the first angle and the second angle is greater than 1 degree and less than 180 degrees; and a first set of vanes and a second set of vanes disposed in the turbine housing, where a vane of the first set of vanes is aligned with the first tongue and a vane of the second set of vanes is aligned with the second tongue.

Methods, apparatus, systems and articles of manufacture are disclosed. A shroud assembly of a gas turbine engine includes: a first shroud arm having a first end and a second end, the first end to couple to an outer wall and the second end to couple to a first shroud pad, and a second shroud arm having a first end and a second end, the first end to couple to the outer wall and the second end to couple to a second shroud pad, at least one of the first shroud pad or the second shroud pad to move radially outward toward the outer wall in response to a rotor blade contacting the at least one of the first shroud pad or the second shroud pad.

A gas turbine engine for an aircraft includes a fan system having a reverse travelling wave first flap mode, Fan RTW, and including a fan located upstream of the engine core; a fan shaft; and a front engine structure arranged to support the fan shaft and having a front engine structure nodding mode comprising a pair of modes at similar, but not equal, natural frequencies in orthogonal directions; and a gearbox. An LP rotor system including the fan system and a gearbox output shaft arranged to drive the fan shaft has a first reverse whirl rotor dynamic mode, Rotor RW, and a first forward whirl rotor dynamic mode, 1FW. The engine has a maximum take-off speed, MTO. A backward whirl frequency margin of:

[00001]$\frac{\begin{array}{l}thelowestfrequencyofeithermodeFanRTW\\ orRotorRWattheMTOspeed\end{array}}{theMTOspeed}$

may be in the range from 15 to 50%.

A power unit control system includes: a gas turbine including a turbine rotor; an energy converter being able to operate as a power generator that generates electric power with rotation of the gas turbine; a battery that stores electric power generated by the energy converter; a reception portion that receives a signal which is transmitted from a device controller that controls a device operating using the electric power stored in the battery or electric power generated by the energy converter; and a control portion that performs rotation speed increase control which increases the rotation speed of the gas turbine to a predetermined rotation speed when a predetermined first signal is received by the reception portion.